Embodiments of the present invention relate to automated operation of mining machines, such as hard rock continuous mining machines.
Traditionally, hard rock excavation is performed using explosive excavation or mechanical excavation. Explosive excavation involves drilling a pattern of small holes into the rock being excavated and loading the holes with explosives. The explosives are then detonated in a sequence designed to fragment the required volume of rock. The fragmented rock is then removed by loading and transport equipment. The violent nature of the rock fragmentation prevents automation of the explosive process and, consequently, makes the process inefficient and unpredictable.
Mechanical excavation eliminates the use of explosives and uses rolling-edge disc cutter technology to fragment rock for excavation. Rolling-edge disc cutters, however, require the application of very large forces to crush and fragment the rock under excavation. For example, the average force required per cutter is about 50 tons and typical peak forces experienced by each cutter are often more than 100 tons. Given these force requirements, it is common to arrange multiple cutters (e.g., 50 cutters) in an array that transverses the rock in closely-spaced, parallel paths. These arrays of cutters can weigh up to 800 tons or more and often require electrical power in the order of thousands of kilowatts. As such, this machinery can only be economically employed on large projects, such as water and power supply tunnels.
Oscillating disc mining machines (often referred to as hard rock continuous miners) overcome many of the issues related to rolling-edge disc cutters. Oscillating disc mining machines use eccentrically-driven disc cutters to cut material. Due to the oscillating nature of the disc cutters, oscillating disc mining machines require less force to fragment material than rolling-edge disc cutters. Accordingly, oscillating disc mining machines are more efficient to operate than rolling-edge disc cutters. Oscillating disc mining machines, however, still suffer from issues related to operator safety and inefficient operation. In particular, to manually operate the machine often requires that an operator be located close to the machine to observe its operation.